Speaker
Description
High-power large-aperture (HPLA) radars are a unique way to probe the population of small bodies near Earth as they can observe both very small particles, down to $10^{-5}$ meters in size, and very large up to hundreds of meters. The smallest particles, called meteoroids, are observable as they enter the Earths atmosphere and produce the phenomenon known as a meteor. Detection of these are possible because the meteoroids produce a plasma which stretch much larger sizes than the particle itself during ablation, and this plasma can scatter the incoming radio waves from the radar. Towards larger sizes, number densities drop fast, so meteors get less frequent and HPLA radars less efficient. Here, optical systems shine (pun intended) with their wide fields of view and often cheaper price than a HPLA facility. But at this point, radars can instead scatter radio waves off the small body itself. Using very long integration times, we can detect meteoroids and asteroids at very long distances and even create radar images of them. Now, there will soon be a new HPLA radar in operation in northern Fenno-Scandinavia called EISCAT_3D. It will be the worlds most advanced radar of its kind. EISCAT_3D consists of a phased array transmitter/receiver site near Skibotn in Norway, one remote receiver site near Kiruna in Sweden and another one near Karesuvanto in Finland. Each site comprises an antenna array with 5.000--10.000 elements. The Skibotn site has a combined 3.37 MW pulsed transmitter power (up to 25\% duty cycle) at an operating frequency of 233 MHz. This unique instrument will enable meteor head echo observations of unprecedented quality while also enabling novel observations of objects in near Earth space, such as minimoons and asteroids.